Prematurity and Occupational Activity during Pregnancy

Abstract

Physical effort in pregnancy may result in premature birth. In the case of working mothers, therefore, it is important to know what kinds of exertion are harmful. The aim of this study was to determine the elements of a given occupation which might constitute possible risk factors in the course of a pregnancy, especially with regard to premature birth. The authors made a survey of 3437 women whose infants were delivered at two maternity hospitals, one in Lyon (a large city) and the other in Haguenau (a small town). Towns of different size were chosen in order to obtain a wider sample of living conditions. Of the 3437 women, 1928 had paid occupations. An analytical breakdown of each job into its diverse components revealed five sources of occupational fatigue: posture, work on industrial machines, physical exertion, mental stress, and environment. The authors constructed an index based on these sources, defining the index scores as ordered variables which could take increasing values as the job became more strenuous with respect to the fatigue source. Premature deliveries occurred in 221 of the total sample of 3437 women (prematurity rate, 6.4 per cent), in 112 of the 1928 working women (prematurity rate, 5.8 per cent), and in 109 of 1509 housewives (prematurity rate, 7.2 per cent). There is no significant difference among these rates, although they may reflect the different sociological profiles of the groups. Since there was no significant difference between the prematurity rates of the two hospitals, the results from both were combined. The occupational category, the weekly working hours, and the daily working timetable were analyzed with regard to prematurity risk. Approximately half of the women had jobs that could be associated with a high prematurity rate. The rate averaged 8.3 per cent among shop staff and